Download video worksheet - Peoria Public Schools

Name __________________________
Bozeman A Beginners Guide to Punnett Squares
Directions: Watch the Paul Anderson video showing how to do punnett squares
using the following website. Answer the related questions to follow.
http://www.bozemanscience.com/beginners-guide-to-punnett-squares/
1. The two sides of a punnett square represent ___________?
2. The boxes on a punnett square represent ________________?
3. In a monohybrid cross, a homozygous purple plant is crossed with a
homozygous recessive white plant. What are the gametes of each parent?
_____ ______ x _______ ______
Show the possible outcomes of the punnett square.
4. What are the possible outcomes of crossing two heterozygous purple
flowered pea plants?
Genotypic ratio ______________________ Phenotypic ratio _______________
5. Incomplete dominance shows only dominant alleles, which come together to
give a third phenotype. What would be the result of crossing a pink (RW)
with another pink (RW) flower?
6. In sex-linked genes, females are XX and males are XY. If a mom is a carrier
for colorblindness, and the dad is a normal male, how many of their children
would be colorblind?
What is the sex of the colorblind child?
7. In a dihybrid cross that Mr. Anderson shows:
a. Write down what R and r mean in pea plants,
b. Write down what Y and y represent in pea plants.
c. What are the genes produced by a plant that is RrYy?
d. Complete a 16-box punnett square to show the outcomes of
crossing two plants that are both heterozygous for the R and Y
genes.
e. What is the phenotypic ratio of the offspring?
8. Cross RrYy x rryy using a 16-box punnett square to show the results.
How can you take a short cut on the 16-box grid?